Information indication method and apparatus

ABSTRACT

This application provides an information indication method and an apparatus. In this application, a sending apparatus generates and sends a first frame, the first frame includes at least one piece of sub-time resource indication information, and each piece of sub-time resource indication information is in a one-to-one correspondence with one of at least one response apparatus. In addition, each piece of sub-time resource indication information includes a time resource at which the corresponding response apparatus sends feedback information for the first frame to the sending apparatus and a time resource at which the sending apparatus sends acknowledgment information for the feedback information to the corresponding response apparatus, so that the at least one response apparatus and the sending apparatus that sends the first frame can simultaneously perform beamforming training, thereby improving effectiveness of beamforming training performed on the sending apparatus and the at least one response apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/882,047, filed on May 22, 2020, which is a continuation ofInternational Application No. PCT/CN2018/113059, filed on Oct. 31, 2018,which claims priority to Chinese Patent Application No. 201711195871.3,filed on Nov. 24, 2017. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments of this application relate to the communications field, andin particular, to an information indication method and an apparatus inthe communications field.

BACKGROUND

IEEE 802.11ad/ay is one of standards for millimeter-wave wirelesscommunication applications in wireless local area network communication.Wide available bandwidth of a millimeter-wave band may bring a highcommunication rate. However, a millimeter-wave signal is severelyattenuated on a channel, and a path loss is large. Therefore, inmillimeter-wave communication, a directional beamforming (beamforming,BF) technology needs to be used to provide an additionaltransmit/receive antenna gain to overcome signal attenuation. Because adirectional beam is used, a data sender/receiver needs to concentrate asending direction/receiving direction of the data sender/receiver withina relatively small angle range. To implement data transmission andreception, a transmit beam direction of the data sender needs to cover areceive beam direction of the data receiver, in other words, a transmitbeam can be aligned with a receive beam. In 802.11ad, a process of beamalignment between a PCP/AP and a STA is referred to as a beamformingtraining process.

In a mesh distribution network, one access point is connected to andcommunicates with a plurality of access points or a plurality ofstations at the same time. Beamforming training needs to be performed onthe access point and the plurality of access points or the plurality ofstations that are connected to the access point before data exchange.How to make the access point and the plurality of access points or theplurality of stations that are connected to the access point performefficient beamforming training is an urgent problem to be resolved.

SUMMARY

Embodiments of this application provide an information indication methodand an apparatus, to improve effectiveness of beamforming trainingperformed on a sending apparatus and at least one response apparatus.

According to a first aspect, an embodiment of this application providesan information indication method, including:

-   -   generating, by a sending apparatus, a first frame, where the        first frame includes time resource indication information; and    -   sending, by the sending apparatus, the first frame to at least        one response apparatus, where the time resource indication        information includes at least one piece of sub-time resource        indication information, each piece of sub-time resource        indication information is in a one-to-one correspondence with        one of the at least one response apparatus, and each piece of        sub-time resource indication information includes a time        resource at which the corresponding response apparatus sends        feedback information for the first frame to the sending        apparatus and a time resource at which the sending apparatus        sends acknowledgment information for the feedback information to        the corresponding response apparatus.

It should be understood that the first frame includes the at least onepiece of sub-time resource indication information, and each piece ofsub-time resource indication information is in a one-to-onecorrespondence with one of the at least one response apparatus. Inaddition, each piece of sub-time resource indication informationincludes the time resource at which the corresponding response apparatussends the feedback information for the first frame to the sendingapparatus and the time resource at which the sending apparatus sends theacknowledgment information for the feedback information to thecorresponding response apparatus, so that the at least one responseapparatus and the sending apparatus that sends the first frame cansimultaneously perform beamforming training, thereby improvingeffectiveness of beamforming training performed on the sending apparatusand the at least one response apparatus.

In a first possible implementation of the first aspect, the first frameincludes a time resource indication field, and the time resourceindication field is used to indicate a time resource at which the atleast one response apparatus sends feedback information for the firstframe to the sending apparatus and a time resource at which the sendingapparatus sends acknowledgment information for the feedback informationto the at least one response apparatus.

Specifically, the time resource indication field is used to carry thetime resource indication information.

With reference to the foregoing possible implementation of the firstaspect, in another possible implementation of the first aspect, thefirst frame further includes a destination indication field, and whenthe destination indication field is a first-type value, the timeresource indication field includes one sub-time resource indicationfield.

With reference to the foregoing possible implementation of the firstaspect, in another possible implementation of the first aspect, thefirst frame further includes a destination indication field, and whenthe destination indication field is a second-type value, the timeresource indication field includes at least two sub-time resourceindication fields.

It should be understood that different values of the destinationindication field indicate different quantities of sub-time resourceindication fields included in the time resource indication field. Whenthe destination indication field is the first-type value, the timeresource indication field includes one sub-time resource indicationfield. When the destination indication field is the second-type value,the time resource indication field includes at least two sub-timeresource indication fields.

Based on this, the sending apparatus may select to send different firstframes based on a quantity of response apparatuses. When the sendingapparatus sends the first frame to one response apparatus, thedestination indication field in the first frame is the first-type value,and the time resource indication field includes one sub-time resourceindication field. When the sending apparatus sends the first frame to atleast two response apparatuses, the destination indication field in thefirst frame is the second-type value, and the time resource indicationfield includes at least two sub-time resource indication fields.Certainly, when the sending apparatus sends the first frame to oneresponse apparatus, the destination indication field in the first frameis the second-type value, and the time resource indication fieldincludes one sub-time resource indication field.

In another possible implementation of the first aspect, each sub-timeresource indication field includes one or any combination of thefollowing pieces of information:

-   -   an identifier subfield used to identify one of the at least two        response apparatuses, and a time resource indication subfield        used by the response apparatus corresponding to the identifier        subfield to send feedback information for the first frame to the        sending apparatus, or a time resource indication subfield used        by the sending apparatus to send acknowledgment information for        the feedback information to the response apparatus corresponding        to the identifier subfield.

In another possible implementation of the first aspect, the first framefurther includes a response apparatus quantity field, and the responseapparatus quantity field is used to indicate a quantity of at least oneresponse apparatus.

In another possible implementation of the first aspect, each sub-timeresource indication field further includes a continuation indicationsubfield or an end indication subfield, the continuation indicationsubfield is used to indicate whether there is a next sub-time resourceindication field in the first frame, and the end indication subfield isused to indicate whether the time resource indication field ends.

In another possible implementation of the first aspect, the identifiersubfield is a MAC address of the corresponding response apparatus, or anID with a length that is obtained through calculation based on the MACaddress of the corresponding response apparatus and that is less thanthat of the MAC address, or a pre-allocated ID.

In another possible implementation of the first aspect, the sendingapparatus receives, at the time resource at which the correspondingresponse apparatus sends the feedback information for the first frame tothe sending apparatus, a feedback frame sent by the correspondingresponse apparatus, where the feedback frame includes the feedbackinformation of the corresponding response apparatus for the first frame.

In another possible implementation of the first aspect, the sendingapparatus sends an acknowledgment frame to the corresponding responseapparatus at the time resource at which the sending apparatus sends theacknowledgment information for the feedback information to thecorresponding response apparatus, where the acknowledgment frameincludes the acknowledgment information for the feedback information.

According to a second aspect, an embodiment of this application providesan information indication method, including:

-   -   receiving, by a response apparatus, a first frame, where the        first frame includes time resource indication information, the        time resource indication information includes at least one piece        of sub-time resource indication information, each piece of        sub-time resource indication information is in a one-to-one        correspondence with one of at least one response apparatus, and        each piece of sub-time resource indication information includes        a time resource at which the corresponding response apparatus        sends feedback information for the first frame to a sending        apparatus and a time resource at which the sending apparatus        sends acknowledgment information for the feedback information to        the corresponding response apparatus; and    -   obtaining, by the response apparatus based on the first frame, a        time resource at which the response apparatus sends feedback        information for the first frame to the sending apparatus and a        time resource at which the sending apparatus sends        acknowledgment information for the feedback information to the        response apparatus.

It should be understood that the first frame includes the at least onepiece of sub-time resource indication information, and each piece ofsub-time resource indication information is in a one-to-onecorrespondence with one of the at least one response apparatus. Inaddition, each piece of sub-time resource indication informationincludes the time resource at which the corresponding response apparatussends the feedback information for the first frame to the sendingapparatus and the time resource at which the sending apparatus sends theacknowledgment information for the feedback information to thecorresponding response apparatus, so that the at least one responseapparatus and the sending apparatus that sends the first frame cansimultaneously perform beamforming training, thereby improvingeffectiveness of beamforming training performed on the sending apparatusand the at least one response apparatus.

In another possible implementation of the second aspect, the methodfurther includes: receiving, by the response apparatus, a second frame,where the second frame includes indication information used to indicatea sending time of the first frame.

In another possible implementation of the second aspect, the receiving,by a response apparatus, a first frame is specifically: receiving, bythe response apparatus, the first frame at the sending time, of thefirst frame, that is indicated by the indication information.

In another possible implementation of the second aspect, the first frameincludes a time resource indication field, and the time resourceindication field is used to indicate a time resource at which the atleast one response apparatus sends feedback information for the firstframe to the sending apparatus and a time resource at which the sendingapparatus sends acknowledgment information for the feedback informationto the at least one response apparatus.

In another possible implementation of the second aspect, the first framefurther includes a destination indication field, and when thedestination indication field is a second-type value, the time resourceindication field includes at least two sub-time resource indicationfields.

In another possible implementation of the second aspect, the first framefurther includes a destination indication field, and when thedestination indication field is a first-type value, the time resourceindication field includes one sub-time resource indication field.

In another possible implementation of the second aspect, each sub-timeresource indication field includes one or any combination of thefollowing pieces of information:

-   -   an identifier subfield used to identify one of at least two        response apparatuses, and a time resource indication subfield        used by the response apparatus corresponding to the identifier        subfield to send feedback information for the first frame to the        sending apparatus, or a time resource indication subfield used        by the sending apparatus to send acknowledgment information for        the feedback information to the response apparatus corresponding        to the identifier subfield.

In another possible implementation of the second aspect, the first framefurther includes a response apparatus quantity field, and the responseapparatus quantity field is used to indicate a quantity of at least tworesponse apparatus.

In another possible implementation of the second aspect, each sub-timeresource indication field further includes a continuation indicationsubfield or an end indication subfield, the continuation indicationsubfield is used to indicate whether there is a next sub-time resourceindication field in the first frame, and the end indication subfield isused to indicate whether the time resource indication field ends.

In another possible implementation of the second aspect, the identifiersubfield is a MAC address of the corresponding response apparatus, or anID with a length that is obtained through calculation based on the MACaddress of the corresponding response apparatus and that is less thanthat of the MAC address, or a pre-allocated ID.

In another possible implementation of the second aspect, the responseapparatus sends a feedback frame to the sending apparatus at the timeresource at which the response apparatus sends the feedback informationfor the first frame to the sending apparatus, where the feedback frameincludes the feedback information of the corresponding responseapparatus for the first frame.

In another possible implementation of the second aspect, the responseapparatus receives, at the time resource at which the sending apparatussends the acknowledgment information for the feedback information to theresponse apparatus, an acknowledgment frame sent by the sendingapparatus, where the acknowledgment frame includes the acknowledgmentinformation for the feedback information.

According to a third aspect, an embodiment of this application providesa sending apparatus, configured to perform the method according to anyone of the first aspect or the possible implementations of the firstaspect. Specifically, the sending apparatus includes a unit configuredto perform the method according to any one of the first aspect or thepossible implementations of the first aspect.

According to a fourth aspect, an embodiment of this application providesa response apparatus, configured to perform the method according to anyone of the second aspect or the possible implementations of the secondaspect. Specifically, the response apparatus includes a unit configuredto perform the method according to any one of the second aspect or thepossible implementations of the second aspect.

According to a fifth aspect, an embodiment of this application providesa sending device, where the sending device includes a transceiver, amemory, and a processor. The transceiver, the memory, and the processorcommunicate with each other by using an internal connection path. Thememory is configured to store an instruction. The processor isconfigured to execute the instruction stored in the memory, to control areceiver to receive a signal and control a transmitter to send a signal.In addition, when the processor executes the instruction stored in thememory, the sending device enables the processor to perform the methodaccording to any one of the first aspect or the possible implementationsof the first aspect.

According to a sixth aspect, an embodiment of this application providesa response device, where the response device includes a transceiver, amemory, and a processor. The transceiver, the memory, and the processorcommunicate with each other by using an internal connection path. Thememory is configured to store an instruction. The processor isconfigured to execute the instruction stored in the memory, to control areceiver to receive a signal and control a transmitter to send a signal.In addition, when the processor executes the instruction stored in thememory, the response device enables the processor to perform the methodaccording to any one of the second aspect or the possibleimplementations of the second aspect.

According to a seventh aspect, an embodiment of this applicationprovides a computer readable medium, configured to store a computerprogram, where the computer program includes an instruction that is usedto perform the method according to any one of the first aspect or thepossible implementations of the first aspect.

According to an eighth aspect, an embodiment of this applicationprovides a computer readable medium, configured to store a computerprogram, where the computer program includes an instruction that is usedto perform the method according to any one of the second aspect or thepossible implementations of the second aspect.

According to a ninth aspect, an embodiment of this application providesa computer program, where the computer program includes an instructionthat is used to perform the method according to any one of the firstaspect or the possible implementations of the first aspect.

According to a tenth aspect, an embodiment of this application providesa computer program, where the computer program includes an instructionthat is used to perform the method according to any one of the secondaspect or the possible implementations of the second aspect.

According to an eleventh aspect, an embodiment of this applicationprovides a chip, where the chip includes a processing circuit and atransceiver pin. The transceiver pin and the processor communicate witheach other by using an internal connection path, and the processorperforms the method according to any one of the first aspect or thepossible implementations of the first aspect, to control a receive pinto receive a signal and control a transmit pin to send a signal.

According to a twelfth aspect, an embodiment of this applicationprovides a chip, where the chip includes a processing circuit and atransceiver pin. The transceiver pin and the processor communicate witheach other by using an internal connection path, and the processorperforms the method according to any one of the second aspect or thepossible implementations of the second aspect, to control a receive pinto receive a signal and control a transmit pin to send a signal.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a mesh distribution network system;

FIG. 2 is a schematic diagram of an application scenario according to anembodiment of this application;

FIG. 3 is a flowchart of a method according to an embodiment of thisapplication;

FIG. 4 is a schematic flowchart according to a first specific embodimentof this application;

FIG. 5 is a schematic diagram of a frame structure of a TDD SSW-A frame;

FIG. 6 is a schematic diagram of another frame structure of a TDD SSW-Aframe;

FIG. 7 is a schematic diagram of another frame structure of a TDD SSW-Aframe;

FIG. 8 is a schematic diagram of another frame structure of a TDD SSW-Aframe;

FIG. 9 is a schematic diagram of a frame structure of a TDD SSW feedbackframe;

FIG. 10 is a schematic diagram of a frame structure of a TDD SSW ACKframe;

FIG. 11 is a schematic flowchart according to a second specificembodiment of this application;

FIG. 12 is a schematic diagram of a frame structure of a TDD SSW-Bframe;

FIG. 13 is a schematic structural diagram of a sending apparatusaccording to an embodiment of this application;

FIG. 14 is a schematic structural diagram of another sending apparatusaccording to an embodiment of this application;

FIG. 15 is a schematic structural diagram of another sending apparatusaccording to an embodiment of this application;

FIG. 16 is a schematic structural diagram of a response apparatusaccording to an embodiment of this application;

FIG. 17 is a schematic structural diagram of another response apparatusaccording to an embodiment of this application;

FIG. 18 shows a plurality of other product forms of a sending apparatusor a response apparatus according to an embodiment of this application;

FIG. 19 is a schematic diagram of another frame structure of a TDD SSW-Aframe;

FIG. 20 is a schematic flowchart according to another embodiment of thisapplication; and

FIG. 21 is a schematic diagram of a frame structure of a TDD SSW frameaccording to another embodiment of this application.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions in the embodiments ofthis application with reference to the accompanying drawings in theembodiments of this application.

It should be understood that the technical solutions of the embodimentsof this application may be applied to various communications systems,such as a global system for mobile communications (global system ofmobile communication, GSM), a code division multiple access (codedivision multiple access, CDMA) system, a wideband code divisionmultiple access (wideband code division multiple access, WCDMA) system,a general packet radio service (general packet radio service, GPRS), along term evolution (long term evolution, LTE) system, an LTE frequencydivision duplex (frequency division duplex, FDD) system, LTE timedivision duplex (time division duplex, TDD) system, a universal mobiletelecommunication system (universal mobile telecommunication system,UMTS), a worldwide interoperability for microwave access (worldwideinteroperability for microwave access, WiMAX) communications system, anda future 5G communications system.

It should be further understood that the technical solutions in theembodiments of this application may be further applied to variouscommunications systems that are based on a non-orthogonal multipleaccess technology, such as a sparse code multiple access (sparse codemultiple access, SCMA) system. Certainly, the SCMA may also have anothername in the communications field. Further, the technical solutions inthe embodiments of this application may be applied to a multicarriertransmission system in which the non-orthogonal multiple accesstechnology is used, such as an orthogonal frequency divisionmultiplexing (orthogonal frequency division multiplexing, OFDM) system,a filter bank multicarrier (filter bank multicarrier, FBMC) system, ageneralized frequency division multiplexing (generalized frequencydivision multiplexing, GFDM) system, or a filtered orthogonal frequencydivision multiplexing (filtered-OFDM, F-OFDM) system in which thenon-orthogonal multiple access technology is used.

It should be further understood that the embodiments of this applicationare applicable to an LTE system and a subsequent evolved system such as5G or other wireless communications systems in which various radioaccess technologies are used, for example, systems in which accesstechnologies such as code division multiple access, frequency divisionmultiple access, time division multiple access, orthogonal frequencydivision multiple access, and single carrier frequency division multipleaccess are used, and particularly, applicable to a scenario in whichchannel information needs to be fed back and/or a two-stage precodingtechnology needs to be used, for example, a wireless network using amassive MIMO technology or a wireless network using a distributedantenna technology.

The foregoing various communications systems include at least onenetwork device. The network device may be a device that communicateswith a terminal device, for example, a base station or a base stationcontroller. Each network device may provide communication coverage for aspecific geographic area, and may communicate with a terminal device(for example, UE) located in the coverage area (a cell). The networkdevice may be a base transceiver station (base transceiver station, BTS)in a GSM system or a code division multiple access (code divisionmultiple access, CDMA) system, a nodeB (nodeB, NB) in a WCDMA system, anevolved NodeB (evolved nodeB, eNB or eNodeB) in an LTE system, or aradio controller in a cloud radio access network (cloud radio accessnetwork, CRAN). Alternatively, the network device may be a relaystation, an access point, a vehicle-mounted device, a wearable device, anetwork side device in a future 5G network, a network device in a futureevolved public land mobile network (public land mobile network, PLMN),or the like.

The foregoing various communications systems further include at leastone terminal device located within coverage of a network device. Theterminal device may be mobile or fixed. The terminal device may be anaccess terminal, user equipment (user equipment, UE), a subscriber unit,a subscriber station, a mobile station, a mobile console, a remotestation, a remote terminal, a mobile device, a user terminal, aterminal, a wireless communications device, a user agent, a userapparatus, or the like. The access terminal may be a cellular phone, acordless phone, a session initiation protocol (session initiationprotocol, SIP) phone, a wireless local loop (wireless local loop, WLL)station, personal digital processing (personal digital assistant, PDA),a handheld device having a wireless communication function, a computingdevice or another processing device connected to a wireless modem, avehicle-mounted device, a wearable device, a terminal device in a future5G network, a terminal device in a future evolved public land mobilenetwork (public land mobile network, PLMN), or the like.

It should be further understood that the embodiments of this applicationare further applicable to a mesh distribution network system. As shownin FIG. 1 , the mesh distribution network system includes a plurality ofAPs and a plurality of STAs, and one AP communicates with a plurality ofother APs or a plurality of other STAs.

FIG. 2 is a schematic diagram of an application scenario according to anembodiment of this application. As shown in FIG. 2 , a sending apparatus100 is connected to and communicates with at least one responseapparatus (201, 202, 203, 204, and 205). Beamforming training needs tobe performed on the sending apparatus 100 and the at least one responseapparatus (201, 202, 203, 204, and 205) before data exchange. How tomake the sending apparatus 100 and the at least one response apparatus(201, 202, 203, 204, and 205) perform efficient beamforming training isan urgent technical problem that needs to be resolved in the embodimentsof this application.

It should be understood that the sending apparatus 100 may be an accesspoint or a station, and the response apparatus (201, 202, 203, 204, and205) may be an access point or a station. This is not limited in thisembodiment of this application.

It should be further understood that FIG. 2 is shown by using only fiveresponse apparatuses (201, 202, 203, 204, and 205) as an example.However, this embodiment of this application is not limited to fiveresponse apparatuses, and FIG. 2 is merely a schematic representation.

An embodiment of this application provides an information indicationmethod. FIG. 3 is a flowchart of a method according to an embodiment ofthis application. As shown in FIG. 3 , an information indication methodincludes the following steps.

S101. A sending apparatus generates a first frame, where the first frameincludes time resource indication information, the time resourceindication information includes at least one piece of sub-time resourceindication information, each piece of sub-time resource indicationinformation is in a one-to-one correspondence with one of at least oneresponse apparatus, and each piece of sub-time resource indicationinformation includes a time resource at which the corresponding responseapparatus sends feedback information for the first frame to the sendingapparatus and a time resource at which the sending apparatus sendsacknowledgment information for the feedback information to thecorresponding response apparatus.

The first frame in S101 is, for example, a TDD SSW-A frame such as a TDDSSW schedule frame.

In S101, as shown in FIG. 2 , the sending apparatus 100 is connected toand communicates with the at least one response apparatus (201, 202,203, 204, and 205), and the sending apparatus 100 generates a firstframe. The first frame includes a time resource indication field, andthe time resource indication field is used to indicate a time resourceat which the at least one response apparatus sends feedback informationfor the first frame to the sending apparatus and a time resource atwhich the sending apparatus sends acknowledgment information for thefeedback information to the at least one response apparatus.

The first frame further includes a destination indication field, andwhen the destination indication field is a second-type value, the timeresource indication field includes at least two sub-time resourceindication fields. The destination indication field is, for example, anRA field. The second-type value is, for example, a multicast addressvalue or a broadcast address value.

When the destination indication field is a second-type value, the timeresource indication field includes at least two sub-time resourceindication fields. Each of the sub-time resource indication fieldsincludes one or any combination of the following pieces of information:an identifier subfield used to identify one of at least two responseapparatuses, and a time resource indication subfield used by theresponse apparatus corresponding to the identifier subfield to sendfeedback information for the first frame to the sending apparatus, or atime resource indication subfield used by the sending apparatus to sendacknowledgment information for the feedback information to the responseapparatus corresponding to the identifier subfield. In a possibleimplementation, each of the sub-time resource indication fields includesan identifier subfield used to identify one of at least two responseapparatuses, a time resource indication subfield used by the responseapparatus corresponding to the identifier subfield to send feedbackinformation for the first frame to the sending apparatus, and a timeresource indication subfield used by the sending apparatus to sendacknowledgment information for the feedback information to the responseapparatus corresponding to the identifier subfield.

When the destination indication field is a first-type value, the timeresource indication field includes one sub-time resource indicationfield. The first-type value is a unicast destination address value. Forexample, if a sending destination of the first frame is a responseapparatus 1, the destination indication field is a MAC address of theresponse apparatus 1 or another address value that can identify theresponse apparatus 1. When the destination indication field is thefirst-type value, and the time resource indication field includes onlyone sub-time resource indication field, the sub-time resource indicationfield includes a time resource indication subfield used by a responseapparatus corresponding to an identifier subfield to send feedbackinformation for the first frame to the sending apparatus, and a timeresource indication subfield used by the sending apparatus to sendacknowledgment information for the feedback information to the responseapparatus corresponding to the identifier subfield, and does not includean identifier subfield used to identify one of the at least one responseapparatus.

For the first frame in which the destination indication field is thesecond-type value, in a possible implementation, the first frame furtherincludes a response apparatus quantity field, and the response apparatusquantity field is used to indicate a quantity of at least two responseapparatuses. The response apparatus quantity field is located before thetime resource indication field. For example, the response apparatusquantity field is located before and adjacent to the time resourceindication field. For another example, the response apparatus quantityfield is located before and spaced from the time resource indicationfield. The response apparatus quantity field is significant for aresponse apparatus that receives the first frame. The response apparatuscan learn of, by using the response apparatus quantity field, a locationof the time resource indication field in the first frame. When parsingbits, the response apparatus may perform correct bit division, todetermine bits of the time resource indication field and bits of a fieldfollowing the time resource indication field.

For the first frame in which the destination indication field is thesecond-type value, in another possible implementation, each of thesub-time resource indication fields further includes a continuationindication subfield, and the continuation indication subfield is used toindicate whether there is a next sub-time resource indication field inthe first frame.

For the first frame in which the destination indication field is thesecond-type value, in another possible implementation, each of thesub-time resource indication fields further includes an end indicationsubfield, and the end indication subfield is used to indicate whetherthe time resource indication field ends.

The continuation indication subfield and the end indication subfield aresignificant for a response apparatus that receives the first frame. Theresponse apparatus can learn of, by using the continuation indicationsubfield or the end indication subfield, a location of the time resourceindication field in the first frame. When parsing bits, the responseapparatus may perform correct bit division, to determine bits of thetime resource indication field and bits of a field following the timeresource indication field.

With reference to the foregoing possible implementations, in a possibleimplementation solution, the identifier subfield is a MAC address of thecorresponding response apparatus, or an ID with a length that isobtained through calculation based on the MAC address of thecorresponding response apparatus and that is less than that of the MACaddress. A shorter identifier subfield indicates fewer overheads ofsending the first frame by a sending apparatus and fewer overheads ofreceiving the first frame by the response apparatus.

S102. The sending apparatus sends the first frame to the at least oneresponse apparatus.

In S102, as shown in FIG. 2 , the sending apparatus 100 sends the firstframe to the at least one response apparatus (201, 202, 203, 204, and205) in a broadcast or multicast manner. Specifically, the RA field inthe first frame may be set to a broadcast address value or a multicastaddress value.

The first frame is a beamforming scanning frame, and the sendingapparatus serially sends a plurality of first frames in a time divisionmanner in one transmit sector, so that the response apparatus separatelyreceives the plurality of first frames by using different receivesectors. In this way, beamforming scanning and alignment are performedbetween the sending apparatus and the response apparatus. If all receivesectors of the response apparatus cannot receive the first frame thatcan be decoded, the response apparatus does not have a receive sectorthat can be aligned with the transmit sector of the sending apparatus.If a specific receive sector of the response apparatus receives thefirst frame that can be decoded, the response apparatus selects thereceive sector as a receive sector aligned with the transmit sector ofthe sending apparatus. If a plurality of receive sectors of the responseapparatus receive the first frame that can be decoded, the responseapparatus selects a receive sector with strongest receive energy as areceive sector aligned with the transmit sector of the sendingapparatus.

It should be noted that the transmit sector described in thespecification of this application has a same meaning as an AWV, asending direction, and a transmit beam. A concept and a meaning of thereceive sector are the same as those of a receiving direction and areceive beam. Details are not described herein.

It should be noted that alignment between the transmit sector and thereceive sector in the specification of this application has a samemeaning as pairing between the transmit beam and a receive beam andalignment between the transmit beam and the receive beam.

S103. The at least one response apparatus receives the first frame.

In S103, as shown in FIG. 2 , the at least one response apparatus (201,202, 203, 204, and 205) receives the first frame. FIG. 3 is shown byusing only two response apparatuses as an example. However, thisembodiment of this application is not limited to two responseapparatuses. FIG. 3 is merely a schematic representation.

As described in S102, when the response apparatus does not have areceive sector that can be aligned with the transmit sector of thesending apparatus, the response apparatus cannot receive the firstframe. When the response apparatus has a receive sector that can bealigned with the transmit sector of the sending apparatus, the responseapparatus receives the first frame. FIG. 3 is shown by using an examplein which both a response apparatus 1 and a response apparatus 2 canreceive the first frame.

S104. The at least one response apparatus sends feedback information forthe first frame to the sending apparatus at a time resource that isindicated by the first frame and at which the corresponding responseapparatus sends the feedback information for the first frame to thesending apparatus.

In S104, after receiving the first frame, the response apparatus obtainsthe time resource at which the corresponding response apparatus sendsthe feedback information for the first frame to the sending apparatus,and sends the feedback information for the first frame to the sendingapparatus at the time resource.

In a possible implementation, the response apparatus sends a feedbackframe to the sending apparatus at the time resource, where the feedbackframe includes the feedback information of the corresponding responseapparatus for the first frame. Specifically, the feedback informationfor the first frame includes information about the transmit sector ofthe sending apparatus, and the first frame sent by the sending apparatusin the transmit sector can be received by the response apparatus, asdescribed in S102. The feedback information for the first frame furtherincludes information about a receive sector, of the response apparatus,that is aligned with the transmit sector of the sending apparatus, asdescribed in S102. The feedback information for the first frame furtherincludes an SNR value of receiving the first frame by the responseapparatus in an aligned receive sector.

In FIG. 3 , two response apparatuses are used as an example. As shown inFIG. 3 , the response apparatus 1 sends a feedback frame 1 to thesending apparatus at a time resource that is indicated by the firstframe and at which the response apparatus 1 sends feedback informationfor the first frame to the sending apparatus. The response apparatus 2sends a feedback frame 2 to the sending apparatus at a time resourcethat is indicated by the first frame and at which the response apparatus2 sends feedback information for the first frame to the sendingapparatus.

S105. The sending apparatus receives the feedback information for thefirst frame.

In S105, the sending apparatus receives at least one feedback frame sentby the at least one response apparatus to the sending apparatus in S104.Specifically, the sending apparatus receives, at the time resource atwhich the corresponding response apparatus sends the feedbackinformation for the first frame to the sending apparatus, the feedbackframe sent by the corresponding response apparatus. The feedback frameincludes the feedback information of the corresponding responseapparatus for the first frame. The sending apparatus can obtain a beamtraining result of the corresponding response apparatus by using thefeedback information for the first frame. For specific content of thefeedback information for the first frame, refer to S104. Details are notdescribed herein again. If the sending apparatus receives no feedbackinformation for the first frame, it indicates that the transmit sectoris not aligned with a receive sector.

S106. After receiving the feedback information for the first frame, thesending apparatus sends acknowledgment information for the feedbackinformation to the corresponding response apparatus at a time resourcethat is indicated by the first frame and at which the sending apparatussends the acknowledgment information for the feedback information to thecorresponding response apparatus.

In S106, in a possible implementation, the sending apparatus sends anacknowledgment frame to the corresponding response apparatus at the timeresource that is indicated by the first frame and at which the sendingapparatus sends the acknowledgment information for the feedbackinformation to the corresponding response apparatus. The acknowledgmentframe includes the acknowledgment information for the feedbackinformation. Specifically, the acknowledgment information for thefeedback information includes information about a transmit sector inwhich the response apparatus sends the feedback frame, an SNR value ofreceiving the feedback frame by the sending apparatus, and otherconfiguration information.

In FIG. 3 , two response apparatuses are used as an example. As shown inFIG. 3 , the sending apparatus sends an acknowledgment frame 1 to theresponse apparatus 1 at a time resource that is indicated by the firstframe and at which the sending apparatus sends acknowledgmentinformation to the response apparatus 1, and the sending apparatus sendsan acknowledgment frame 2 to the response apparatus 2 at a time resourcethat is indicated by the first frame and at which the sending apparatussends acknowledgment information to the response apparatus 2.

The sending apparatus may send acknowledgment frames to responseapparatuses one by one after receiving feedback frames of all theresponse apparatuses, as shown in FIG. 3 . Alternatively, the sendingapparatus may send an acknowledgment frame to a corresponding responseapparatus after receiving a feedback frame of the response apparatus,and then the sending apparatus receives a feedback frame of anotherresponse apparatus, and sends an acknowledgment frame to thecorresponding response apparatus. This is not limited in this embodimentof this application. A time at which a response apparatus sends afeedback frame and a time at which the sending apparatus sends anacknowledgment frame are indicated by the first frame. Specifically, thesending apparatus may configure indication information of the firstframe, and a response apparatus performs execution based on theindication information of the first frame.

In this embodiment of this application, the first frame used forbeamforming scanning includes the at least one piece of sub-timeresource indication information, each piece of sub-time resourceindication information is in a one-to-one correspondence with one of theat least one response apparatus, the sending apparatus sends the firstframe to the at least one response apparatus, and the at least oneresponse apparatus sends, to the sending apparatus at the correspondingtime resource indicated by the first frame, the feedback frame used forfeeding back beamforming scanning information, so that the at least oneresponse apparatus and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least oneresponse apparatus.

Further, in this embodiment of this application, when the destinationindication field in the first frame used for beamforming scanning is thesecond-type value, the first frame includes the at least two sub-timeresource indication fields, each of the sub-time resource indicationfields is in a one-to-one correspondence with one of the at least tworesponse apparatuses, the sending apparatus sends the first frame to theat least two response apparatuses, and the at least two responseapparatuses send, to the sending apparatus at corresponding timeresources indicated by the first frame, feedback frames used for feedingback beamforming scanning information, so that the at least two responseapparatuses and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least tworesponse apparatuses.

Certainly, when the destination indication field in the first frame usedfor beamforming scanning is the second-type value, the first frame mayalternatively include one sub-time resource indication field. Anidentifier subfield value of the sub-time resource indication field isan address of a response apparatus, and the sub-time resource indicationfield includes the identifier subfield (the address of the responseapparatus), a time resource indication subfield used by the responseapparatus corresponding to the identifier subfield to send feedbackinformation for the first frame to the sending apparatus, and a timeresource indication subfield used by the sending apparatus to sendacknowledgment apparatus for the feedback information to the responseapparatus corresponding to the identifier subfield.

In a second embodiment of this application, before the sending apparatusgenerates and sends the first frame that includes the time resourceindication information, the sending apparatus generates and sends asecond frame, where the second frame includes indication informationused to indicate a sending time of the first frame, and the sendingapparatus sends the first frame to the at least one response apparatusat the sending time, of the first frame, that is indicated by theindication information.

A difference between the second embodiment of this application and theforegoing embodiment of this application lies in that the second frameis a beamforming scanning frame that includes the indication informationused to indicate the sending time of the first frame, and the sendingapparatus serially sends a plurality of second frames in a time divisionmanner in one transmit sector, so that the response apparatus separatelyreceives the plurality of second frames by using different receivesectors. If all receive sectors of the response apparatus cannot receivethe second frame that can be decoded, the response apparatus does nothave a receive sector that can be aligned with the transmit sector ofthe sending apparatus. If a specific receive sector of the responseapparatus receives the second frame that can be decoded, the responseapparatus selects the receive sector as a receive sector aligned withthe transmit sector of the sending apparatus. If a plurality of receivesectors of the response apparatus receive the second frame that can bedecoded, the response apparatus selects a receive sector with strongestreceive energy as a receive sector aligned with the transmit sector ofthe sending apparatus.

The second frame includes the indication information used to indicatethe sending time of the first frame. Specifically, the second frameincludes an indication field used to indicate the sending time of thefirst frame. In other words, the second frame in the second embodimentof this application is a beamforming scanning frame that includes theindication field used to indicate the sending time of the first frame.

After serially sending the plurality of second frames in a time divisionmanner in one transmit sector, the sending apparatus sends, by using thesame transmit sector at the sending time, of the first frame, that isindicated by the second frame, the first frame that includes the timeresource indication information. Correspondingly, if the responseapparatus can receive the second frame that can be decoded, the responseapparatus further needs to receive, by using a receive sector thatreceives the second frame, the first frame at the sending time, of thefirst frame, that is indicated by the second frame, to obtain the atleast one piece of sub-time resource indication information in the firstframe. If the response apparatus cannot receive the second frame thatcan be decoded, the response apparatus does not have a receive sectorthat can be aligned with the transmit sector of the sending apparatus,and the response apparatus cannot receive the second frame sent by thesending apparatus in the transmit sector or the first frame sent by thesending apparatus in the transmit sector.

In the second embodiment of this application, the second frame is abeamforming scanning frame, to be specific, the sending apparatusserially sends the plurality of second frames in a time division mannerin one transmit sector, and the response apparatus separately receivesthe plurality of second frames by using different receive sectors. Inthis way, beamforming scanning and alignment are performed between thesending apparatus and the response apparatus.

In the foregoing embodiment of this application, the first frame is abeamforming scanning frame, to be specific, the sending apparatusserially sends the plurality of first frames in a time division mannerin one transmit sector, so that the response apparatus separatelyreceives the plurality of first frames by using different receivesectors. In this way, beamforming scanning and alignment are performedbetween the sending apparatus and the response apparatus.

In the second embodiment of this application, the second frame includesonly the indication field used to indicate the sending time of the firstframe. In the foregoing embodiment of this application, the first frameincludes the time resource indication field with a relatively large datavolume. In the second embodiment of this application, a sum of overheadsof serially sending, by the sending apparatus, the plurality of secondframes in a time division manner in one transmit sector and overheads ofsending, by the sending apparatus, only one first frame in one transmitsector is far less than overheads of serially sending, by the sendingapparatus, the plurality of first frames in a time division manner inone transmit sector in the foregoing embodiment of this application.

In this embodiment of this application, in addition to distinguishing astructure of the first frame by using a value of the destinationindication field, a TDD beamforming frame subtype field of the firstframe may also be used to distinguish the structure of the first frame,as shown in FIG. 5 .

The value of the destination indication field is used to distinguish thestructure of the first frame. Specifically, when the destinationindication field is the first-type value, the time resource indicationfield includes one sub-time resource indication field, where thesub-time resource indication field includes the time resource indicationsubfield used by the response apparatus corresponding to the identifiersubfield to send the feedback information for the first frame to thesending apparatus, and/or the time resource indication subfield used bythe sending apparatus to send the acknowledgment information for thefeedback information to the response apparatus corresponding to theidentifier subfield. When the destination indication field is thesecond-type value, the time resource indication field includes at leastone sub-time resource indication field, and each sub-time resourceindication field includes one or any combination of the following piecesof information: the identifier subfield used to identify one of the atleast two response apparatuses, and the time resource indicationsubfield used by the response apparatus corresponding to the identifiersubfield to send the feedback information for the first frame to thesending apparatus, or the time resource indication subfield used by thesending apparatus to send the acknowledgment information for thefeedback information to the response apparatus corresponding to theidentifier subfield.

As shown in FIG. 5 , the TDD beamforming frame subtype field of thefirst frame is used to distinguish the structure of the first frame.Specifically, the subtype field has 2 bits. When the subtype field is00, the time resource indication field includes one sub-time resourceindication field, where the sub-time resource indication field includesthe time resource indication subfield used by the response apparatuscorresponding to the identifier subfield to send the feedbackinformation for the first frame to the sending apparatus, and/or thetime resource indication subfield used by the sending apparatus to sendthe acknowledgment information for the feedback information to theresponse apparatus corresponding to the identifier subfield. When thesubtype field is 11, the time resource indication field includes atleast one sub-time resource indication field, and each sub-time resourceindication field includes one or any combination of the following piecesof information: the identifier subfield used to identify one of the atleast two response apparatuses, and the time resource indicationsubfield used by the response apparatus corresponding to the identifiersubfield to send the feedback information for the first frame to thesending apparatus, or the time resource indication subfield used by thesending apparatus to send the acknowledgment information for thefeedback information to the response apparatus corresponding to theidentifier subfield.

Certainly, a reserved bit in the first frame may also be used todistinguish the structure of the first frame.

The following provides two specific embodiments of this application.

FIG. 4 is a schematic flowchart according to a first specific embodimentof this application. As shown in FIG. 4 , an information indicationmethod includes the following steps.

S200. A sending apparatus generates a TDD SSW-A frame.

S200 is not shown in FIG. 4 .

The TDD SSW-A frame generated by the sending apparatus is a beamformingscanning frame, and a frame structure of the TDD SSW-A frame is shown inFIG. 5 . The TDD SSW-A frame includes a frame control field, a durationfield, a destination indication field, a source indication field, a TDDbeamforming control field, a frame body field, and an FCS check field.The frame body field includes a transmit beam index number, a CDOWNfield, a time resource indication field with a variable length, and aperiodictity field. The time resource indication field with a variablelength is used to indicate a time resource at which at least oneresponse apparatus sends feedback information for the first frame to thesending apparatus and a time resource at which the sending apparatussends acknowledgment information for the feedback information to the atleast one response apparatus. Particularly, when the destinationindication field is a multicast address value or a broadcast addressvalue, the time resource indication field with a variable length is usedto indicate time resources at which at least two response apparatusessend feedback information for the first frame to the sending apparatusand time resources at which the sending apparatus sends acknowledgmentinformation for the feedback information to the at least two responseapparatuses.

Further, as shown in FIG. 6 , the time resource indication fieldincludes at least one sub-time resource indication field, and eachsub-time resource indication field includes an identifier subfield usedto identify one of the at least one response apparatus, and a timeresource indication subfield used by the response apparatuscorresponding to the identifier subfield to send feedback informationfor the first frame to the sending apparatus, or a time resourceindication subfield used by the sending apparatus to send acknowledgmentinformation for the feedback information to the response apparatuscorresponding to the identifier subfield.

Further, in another possible implementation, as shown in FIG. 19 , thetime resource indication field includes at least one sub-time resourceindication field. A first sub-time resource indication field includes anidentifier subfield used to identify one of the at least one responseapparatus, and a time resource indication subfield used by the responseapparatus corresponding to the identifier subfield to send feedbackinformation for the first frame to the sending apparatus, or a timeresource indication subfield used by the sending apparatus to sendacknowledgment information for the feedback information to the responseapparatus corresponding to the identifier subfield. A second sub-timeresource indication field, a third sub-time resource indication field, .. . , and an N^(th) sub-time resource indication field each include onlyan identifier subfield used to identify one of the at least one responseapparatus, but do not include a time resource indication subfield usedby the response apparatus corresponding to the identifier subfield tosend feedback information for the first frame to the sending apparatusand a time resource indication subfield used by the sending apparatus tosend acknowledgment information for the feedback information to theresponse apparatus corresponding to the identifier subfield. Timeresources of the second sub-time resource indication field, the thirdsub-time resource indication field, . . . , and the N^(th) sub-timeresource indication field are based on the time resource indicationsubfield used by the response apparatus corresponding to the identifiersubfield to send the feedback information for the first frame to thesending apparatus and the time resource indication subfield used by thesending apparatus to send the acknowledgment information for thefeedback information to the response apparatus corresponding to theidentifier subfield in the first sub-time resource indication field.

For the first frames shown in FIG. 6 and FIG. 19 , when a destinationaddress value of the first frame is a second-type value, the timeresource indication field in the first frame includes at least twosub-time resource indication fields.

Based on a TDD SSW-A frame structure shown in FIG. 6 , further, in apossible implementation, as shown in FIG. 7 , the TDD SSW-A framefurther includes a response apparatus quantity field, and the responseapparatus quantity field is used to indicate a quantity of at least tworesponse apparatuses.

Based on a TDD SSW-A frame structure shown in FIG. 6 , further, inanother possible implementation, as shown in FIG. 8 , the sub-timeresource indication field further includes a continuation indicationsubfield or an end indication subfield, the continuation indicationsubfield is used to indicate whether there is a next sub-time resourceindication field in the first frame, and the end indication subfield isused to indicate whether the time resource indication field ends.

In the foregoing various TDD SSW-A frames, an identifier subfield of aresponse apparatus in a sub-time resource indication field is a MACaddress of the response apparatus, an ID with a length that is obtainedthrough calculation based on the MAC address and that is less than thatof the MAC address, or a pre-allocated ID, for example, an 8-bit IDobtained through calculation based on a 48-bit MAC address by using anXX algorithm. Apparently, a smaller quantity of bits in the identifiersubfield of the response apparatus leads to smaller overheads of thefirst frame.

S201. The sending apparatus sends the TDD SSW-A frame to at least oneresponse apparatus.

In S201, the sending apparatus may send the TDD SSW-A frame to aresponse apparatus in a unicast manner. Specifically, the sendingapparatus sends the TDD SSW-A frame whose destination indication fieldis a first-type value to a destination device, where the first-typevalue is an address of the destination device, for example, a MACaddress of the destination device.

The sending apparatus may further send the TDD SSW-A frame to the atleast one response apparatus in a broadcast or multicast manner.Specifically, the sending apparatus sends the TDD SSW-A frame whosedestination indication field is a second-type value to a destinationdevice, where the second-type value is a multicast address value or abroadcast address value. The destination indication field in the TDDSSW-A frame is the second-type value, and a time resource indicationfield in the TDD SSW-A frame includes at least one sub-time resourceindication field, for example, includes one sub-time resource indicationfield, or includes two sub-time resource indication fields, or includesN sub-time resource indication fields.

The TDD SSW-A frame is a beamforming scanning frame, and the sendingapparatus serially sends a plurality of TDD SSW-A frames in a timedivision manner in one transmit sector, so that the response apparatusseparately receives the TDD SSW-A frames by using different receivesectors. In this way, beamforming scanning and alignment are performedbetween the sending apparatus and the response apparatus. Each of the atleast one response apparatus separately receives the TDD SSW-A frames byusing different receive sectors of the response apparatus. In this way,beamforming scanning and alignment are performed between the sendingapparatus and each response apparatus. If all receive sectors of theresponse apparatus cannot receive the TDD SSW-A frame that can bedecoded, the response apparatus does not have a receive sector that canbe aligned with the transmit sector of the sending apparatus. If aspecific receive sector of the response apparatus receives the TDD SSW-Aframe that can be decoded, the response apparatus selects the receivesector as a receive sector aligned with the transmit sector of thesending apparatus. If a plurality of receive sectors of the responseapparatus receive the TDD SSW-A frame that can be decoded, the responseapparatus selects a receive sector with strongest receive energy as areceive sector aligned with the transmit sector of the sendingapparatus.

S202. A response apparatus that receives the TDD SSW-A frame returns aTDD SSW feedback frame to the sending apparatus at a moment indicated by“a time resource indication subfield used by a response apparatus N tosend feedback information for the first frame to the sending apparatus”in the TDD SSW-A frame.

In S202, for a condition of receiving the TDD SSW-A frame by theresponse apparatus, refer to S201. If the response apparatus has areceive sector that can be aligned with the transmit sector of thesending apparatus, the response apparatus can receive the TDD SSW-Aframe.

As shown in FIG. 4 , a response apparatus 1 that receives the TDD SSW-Aframe returns a TDD SSW feedback frame to the sending apparatus at amoment indicated by “a time resource indication subfield used by theresponse apparatus 1 to send feedback information for the first frame”in the TDD SSW-A frame, and the response apparatus N that receives theTDD SSW-A frame returns the TDD SSW feedback frame to the sendingapparatus at the moment indicated by “the time resource indicationsubfield used by the response apparatus N to send the feedbackinformation for the first frame” in the TDD SSW-A frame.

The TDD SSW feedback frame is used by the response apparatus to returnfeedback information for the TDD SSW-A frame to the sending apparatus.As shown in FIG. 9 , the TDD SSW feedback frame includes a frame controlfield, a duration field, a destination indication field, a sourceindication field, a TDD beamforming control field, a frame body field,and an FCS check field, and the frame body field includes an indexnumber of a transmit beam used by a sending apparatus to send the TDDSSW-A frame, an index number of a receive beam used by a responseapparatus to receive the TDD SSW-A frame, an SNR value of receiving theTDD SSW-A frame by the response apparatus, and a reserved bit.

Transmit/receive beam reciprocity exists between the sending apparatusand the response apparatus. The response apparatus that receives the TDDSSW-A frame sends the TDD SSW feedback frame to the sending apparatus byusing a beam that is used to receive the TDD SSW-A frame, and thesending apparatus receives the TDD SSW feedback frame by using a beamthat is used to send the TDD SSW-A frame.

S203. The sending apparatus that receives the TDD SSW feedback framesends a TDD SSW ACK frame to the response apparatus N at a momentindicated by “a time resource indication subfield used by the sendingapparatus to send acknowledgment information for the feedbackinformation to the response apparatus N” in the TDD SSW-A frame.

As shown in FIG. 4 , the sending apparatus sends a TDD SSW ACK frame tothe response apparatus 1 at a moment indicated by “a time resourceindication subfield used by the sending apparatus to send acknowledgmentinformation for the feedback information to the response apparatus 1” inthe TDD SSW-A frame, and the sending apparatus sends the TDD SSW ACKframe to the response apparatus N at the moment indicated by “the timeresource indication subfield used by the sending apparatus to send theacknowledgment information for the feedback information to the responseapparatus N” in the TDD SSW-A frame.

The TDD SSW ACK frame is used by the sending apparatus to sendacknowledgment information for the TDD SSW feedback frame to theresponse apparatus. As shown in FIG. 10 , the TDD SSW ACK frame includesan index number of a transmit beam used by a response apparatus to senda TDD SSW feedback frame, an SNR value of receiving the TDD SSW feedbackframe by a sending apparatus, a reserved bit, and some otherinformation.

The response apparatus returns the TDD SSW feedback frame at the momentindicated by “the time resource indication subfield used by the responseapparatus N to send the feedback information for the first frame to thesending apparatus” in the TDD SSW-A frame. The sending apparatus sendsthe TDD SSW ACK frame at the moment indicated by “the time resourceindication subfield used by the sending apparatus to send theacknowledgment information for the feedback information to the responseapparatus N” in the TDD SSW-A frame. The sending apparatus and theresponse apparatus can perform other communication within a period fromthe moment indicated by “the time resource indication subfield used bythe response apparatus N to send the feedback information for the firstframe to the sending apparatus” to the moment indicated by “the timeresource indication subfield used by the sending apparatus to send theacknowledgment information for the feedback information to the responseapparatus N”, as shown in FIG. 4 , this embodiment of this applicationsets no limitation thereto.

In the foregoing first specific embodiment of this application, the TDDSSW-A frame includes at least one sub-time resource indication field,and each sub-time resource indication field is in a one-to-onecorrespondence with one of the at least one response apparatus. Thesending apparatus sends the TDD SSW-A frame to the at least one responseapparatus, and the at least one response apparatus sends a TDD SSWfeedback frame to the sending apparatus at a corresponding momentindicated by the TDD SSW-A frame, so that the at least one responseapparatus and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least oneresponse apparatus.

Further, the sending apparatus sends a TDD SSW ACK frame to the responseapparatus at a corresponding moment indicated by the TDD SSW-A frame, tofurther confirm the TDD SSW feedback frame, and further improve abeamforming training process between the sending apparatus and the atleast one response apparatus.

The following provides a second specific embodiment of this application.

A difference between the second specific embodiment of this applicationand the foregoing first specific embodiment of this application lies inthat a TDD SSW-B frame is a beamforming scanning frame and includesindication information used to indicate a sending time of the TDD SSWschedule frame, and “time resource indication information used toinstruct at least one response apparatus to send feedback informationfor the first frame to the sending apparatus and time resourceindication information used by the sending apparatus to sendacknowledgment information for the feedback information to the at leastone response apparatus” are carried in the TDD SSW schedule frame.

FIG. 11 is a schematic flowchart according to a second specificembodiment of this application. As shown in FIG. 11 , an informationindication method includes the following steps.

S300. A sending apparatus generates a TDD SSW-B frame and a TDD SSWschedule frame.

S300 is not shown in FIG. 11 .

The TDD SSW-B frame generated by the sending apparatus is a beamformingscanning frame, and a difference between the TDD SSW-B frame and a TDDSSW-A frame lies in that:

-   -   1. The TDD SSW-B frame includes indication information used to        indicate a sending time of the TDD SSW schedule frame, but does        not include time resource indication information used to        instruct at least one response apparatus to send feedback        information for the first frame to the sending apparatus and        time resource indication information used by the sending        apparatus to send acknowledgment information for the feedback        information to the at least one response apparatus. “The time        resource indication information used to instruct the at least        one response apparatus to send the feedback information for the        first frame to the sending apparatus and the time resource        indication information used by the sending apparatus to send the        acknowledgment information for the feedback information to the        at least one response apparatus” are carried in the TDD SSW        schedule frame.    -   2. The TDD SSW-A frame in the first specific embodiment of this        application directly includes time resource indication        information used to instruct at least one response apparatus to        send feedback information for the first frame to the sending        apparatus and time resource indication information used by the        sending apparatus to send acknowledgment information for the        feedback information to the at least one response apparatus.

A frame structure of the TDD SSW-B frame is shown in FIG. 12 , the TDDSSW-B frame includes a frame control field, a duration field, adestination indication field, a source indication field, a TDDbeamforming control field, a frame body field, and an FCS check field,and the frame body field includes an index number of a transmit beamused by the sending apparatus to send the TDD SSW-B frame, a CDOWNfield, a TDD SSW schedule frame sending time indication field, aperiodictity field, and a reserved field.

A frame structure of the TDD SSW schedule frame is the same as the framestructure of the TDD SSW-A frame in the first specific embodiment ofthis application, and details are not described herein again.

S301. The sending apparatus sends the TDD SSW-B frame to at least oneresponse apparatus.

In S301, the TDD SSW-B frame is a beamforming scanning frame thatincludes the indication information used to indicate the sending time ofthe TDD SSW schedule frame, and the sending apparatus serially sends aplurality of TDD SSW-B frames in a time division manner in one transmitsector, so that the response apparatus separately receives the TDD SSW-Bframes by using different receive sectors. In this way, beamformingscanning and alignment are performed between the sending apparatus andthe response apparatus. Each of the at least one response apparatusseparately receives the TDD SSW-B frames by using different receivesectors of the response apparatus. In this way, beamforming scanning andalignment are performed between the sending apparatus and each responseapparatus. If all receive sectors of the response apparatus cannotreceive the TDD SSW-B frame that can be decoded, the response apparatusdoes not have a receive sector that can be aligned with the transmitsector of the sending apparatus. If a specific receive sector of theresponse apparatus receives the TDD SSW-B frame that can be decoded, theresponse apparatus selects the receive sector as a receive sectoraligned with the transmit sector of the sending apparatus. If aplurality of receive sectors of the response apparatus receive the TDDSSW-B frame that can be decoded, the response apparatus selects areceive sector with strongest receive energy as a receive sector alignedwith the transmit sector of the sending apparatus.

A response apparatus aligned with the transmit sector of the sendingapparatus receives the TDD SSW-B frame, and obtains, by using the TDDSSW schedule frame sending time indication field in the TDD SSW-B frame,the time at which the sending apparatus sends the TDD SSW scheduleframe, the sending apparatus sends the TDD SSW schedule frame by usingthe same transmit sector, and the response apparatus receives the TDDSSW schedule frame by using the same receive sector. The TDD SSWschedule frame carries “the time resource indication information used toinstruct the at least one response apparatus to send the feedbackinformation for the first frame to the sending apparatus and the timeresource indication information used by the sending apparatus to sendthe acknowledgment information for the feedback information to the atleast one response apparatus”, and the response apparatus obtainscorresponding information.

S302. The sending apparatus sends the TDD SSW schedule frame to the atleast one response apparatus.

In S302, as described in S301, the sending apparatus sends the TDD SSWschedule frame to the at least one response apparatus at a momentindicated by the TDD SSW schedule frame sending time indication field inthe TDD SSW-B frame.

S303. A response apparatus that receives the TDD SSW schedule framereturns a TDD SSW feedback frame to the sending apparatus at a momentindicated by “a time resource indication subfield used by a responseapparatus N to send feedback information for the first frame to thesending apparatus” in the TDD SSW schedule frame.

S304. The sending apparatus that receives the TDD SSW feedback framesends a TDD SSW ACK frame to the response apparatus N at a momentindicated by “a time resource indication subfield used by the sendingapparatus to send acknowledgment information for the feedbackinformation to the response apparatus N” in the TDD SSW schedule frame.

S303 is similar to S202, and S304 is similar to S203. Details are notdescribed herein again.

In the second specific embodiment of this application, a quantity ofbits of the beamforming scanning frame, namely, the TDD SSW-B frame,that includes the indication information used to indicate the sendingtime of the TDD SSW schedule frame is far less than that of thebeamforming scanning frame, namely, the TDD SSW-A frame, in the firstspecific embodiment of this application. A process of beamformingscanning is as follows: A sending apparatus serially sends a pluralityof beamforming scanning frames in a time division manner in one transmitsector, so that a response apparatus separately receives the beamformingscanning frames by using different receive sectors. When the quantity ofbits of the TDD SSW-B frame is far less than that of the TDD SSW-Aframe, a sum of overheads of serially sending, by the sending apparatus,the plurality of TDD SSW-B frames in a time division manner in onetransmit sector and overheads of sending, by the sending apparatus, onlyone TDD SSW schedule frame in one transmit sector is far less thanoverheads of serially sending, by the sending apparatus, a plurality ofTDD SSW-A frames in a time division manner in one transmit sector. Forclarity, FIG. 4 and FIG. 11 may be compared to obtain the conclusion inthis paragraph.

An embodiment of this application further provides a sending apparatus.It should be understood that the sending apparatus in this embodiment ofthis application has any function of the sending apparatus in theforegoing methods.

FIG. 13 is a schematic structural diagram of a sending apparatusaccording to an embodiment of this application. As shown in FIG. 13 , asending apparatus includes:

-   -   a first frame generation unit 101, configured to generate a        first frame, where the first frame includes time resource        indication information; and    -   a first frame sending unit 102, configured to send the first        frame to at least one response apparatus, where the time        resource indication information includes at least one piece of        sub-time resource indication information, each piece of sub-time        resource indication information is in a one-to-one        correspondence with one of the at least one response apparatus,        and each piece of sub-time resource indication information        includes a time resource at which the corresponding response        apparatus sends feedback information for the first frame to the        sending apparatus and a time resource at which the sending        apparatus sends acknowledgment information for the feedback        information to the corresponding response apparatus.

In this embodiment of this application, the first frame that isgenerated and sent by the sending apparatus and that is used forbeamforming scanning includes the at least one piece of sub-timeresource indication information, each piece of sub-time resourceindication information is in a one-to-one correspondence with one of theat least one response apparatus, the sending apparatus sends the firstframe to the at least one response apparatus, and the at least oneresponse apparatus sends, to the sending apparatus at a correspondingtime resource indicated by the first frame, a feedback frame used forfeeding back beamforming scanning information, so that the at least oneresponse apparatus and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least oneresponse apparatus.

Further, in this embodiment of this application, when a destinationindication field in the first frame used for beamforming scanning is asecond-type value, the first frame includes at least two sub-timeresource indication fields, each of the sub-time resource indicationfields is in a one-to-one correspondence with one of at least tworesponse apparatuses, the sending apparatus sends the first frame to theat least two response apparatuses, and the at least two responseapparatuses send, to the sending apparatus at corresponding timeresources indicated by the first frame, feedback frames used for feedingback beamforming scanning information, so that the at least two responseapparatuses and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least tworesponse apparatuses.

Based on the foregoing sending apparatus, an embodiment of thisapplication further provides another sending apparatus. It should beunderstood that the sending apparatus in this embodiment of thisapplication has any function of the sending apparatus in the foregoingmethods.

FIG. 14 is a schematic structural diagram of another sending apparatusaccording to an embodiment of this application. As shown in FIG. 14 , asending apparatus includes:

-   -   a first frame generation unit 101 and a first frame sending unit        102, where functions of the first frame generation unit 101 and        the first frame sending unit 102 are the same as those described        in the foregoing embodiment, and details are not described        herein again;    -   a feedback frame receiving unit 103, configured to receive, at        the time resource at which the corresponding response apparatus        sends the feedback information for the first frame to the        sending apparatus, a feedback frame sent by the corresponding        response apparatus, where the feedback frame includes the        feedback information of the corresponding response apparatus for        the first frame; and    -   an acknowledgment frame sending unit 104, configured to send an        acknowledgment frame to the corresponding response apparatus at        the time resource at which the sending apparatus sends the        acknowledgment information for the feedback information to the        corresponding response apparatus, where the acknowledgment frame        includes the acknowledgment information for the feedback        information.

Based on the sending apparatus shown in FIG. 14 , an embodiment of thisapplication further provides another sending apparatus shown in FIG. 15. The following units are added to the sending apparatus shown in FIG.15 based on the sending apparatus shown in FIG. 14 :

-   -   a second frame generation unit 105, configured to generate a        second frame, where the second frame includes indication        information used to indicate a sending time of the first frame;        and    -   a second frame sending unit 106, configured to send the second        frame to the at least one response apparatus.

An embodiment of this application further provides a response apparatus.It should be understood that the response apparatus in this embodimentof this application has any function of the response apparatus in theforegoing methods.

FIG. 16 is a schematic structural diagram of a response apparatusaccording to an embodiment of this application. As shown in FIG. 16 , aresponse apparatus includes:

-   -   a first frame receiving unit 201, configured to receive a first        frame, where the first frame includes time resource indication        information, the time resource indication information includes        at least one piece of sub-time resource indication information,        each piece of sub-time resource indication information is in a        one-to-one correspondence with one of at least one response        apparatus, and each piece of sub-time resource indication        information includes a time resource at which the corresponding        response apparatus sends feedback information for the first        frame to a sending apparatus and a time resource at which the        sending apparatus sends acknowledgment information for the        feedback information to the corresponding response apparatus;        and    -   a time resource obtaining unit 202, configured to obtain, based        on the first frame, a time resource at which the response        apparatus sends feedback information for the first frame to the        sending apparatus and a time resource at which the sending        apparatus sends acknowledgment information for the feedback        information to the response apparatus.

In this embodiment of this application, the first frame that isgenerated and sent by the sending apparatus and that is used forbeamforming scanning includes the at least one piece of sub-timeresource indication information, each piece of sub-time resourceindication information is in a one-to-one correspondence with one of theat least one response apparatus, the sending apparatus sends the firstframe to the at least one response apparatus, and the at least oneresponse apparatus sends, to the sending apparatus at a correspondingtime resource indicated by the first frame, a feedback frame used forfeeding back beamforming scanning information, so that the at least oneresponse apparatus and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least oneresponse apparatus.

Further, in this embodiment of this application, when a destinationindication field in the first frame used for beamforming scanning is asecond-type value, the first frame includes at least two sub-timeresource indication fields, each of the sub-time resource indicationfields is in a one-to-one correspondence with one of at least tworesponse apparatuses, the sending apparatus sends the first frame to theat least two response apparatuses, and the at least two responseapparatuses send, to the sending apparatus at corresponding timeresources indicated by the first frame, feedback frames used for feedingback beamforming scanning information, so that the at least two responseapparatuses and the sending apparatus can simultaneously performbeamforming training, thereby improving effectiveness of beamformingtraining performed on the sending apparatus and the at least tworesponse apparatuses.

Based on the response apparatus shown in FIG. 16 , an embodiment of thisapplication further provides another response apparatus shown in FIG. 17. The following units are added to the response apparatus shown in FIG.17 based on the response apparatus shown in FIG. 16 :

a feedback frame sending unit 203, configured to send a feedback frameto the sending apparatus at the time resource at which the responseapparatus sends the feedback information for the first frame to thesending apparatus, where the feedback frame includes the feedbackinformation of the corresponding response apparatus for the first frame;and an acknowledgment frame receiving unit 204, configured to receive,at the time resource at which the sending apparatus sends theacknowledgment information for the feedback information to thecorresponding response apparatus, an acknowledgment frame sent by thesending apparatus, where the acknowledgment frame includes theacknowledgment information for the feedback information.

An embodiment of this application further provides another responseapparatus, and the following unit is added based on the responseapparatus shown in FIG. 17 :

-   -   a second frame receiving unit, configured to receive a second        frame, where the second frame includes indication information        used to indicate a sending time of the first frame.

Referring back to FIG. 2 , the foregoing sending apparatus is thesending apparatus 100 in FIG. 2 , and the foregoing response apparatusis any response apparatus in FIG. 2 , for example, the responseapparatus 201, the response apparatus 202, the response apparatus 203,the response apparatus 204, and the response apparatus 205.

In addition to the foregoing product forms, the sending apparatus andthe response apparatus described in this application may further havethe following product forms:

FIG. 18 shows a plurality of other product forms of a sending apparatusor a response apparatus according to an embodiment of this application.As shown in FIG. 18 , in a possible product form, the sending apparatusor the response apparatus may be implemented by using a bus 1801 as ageneral bus architecture. As shown in FIG. 18 , the bus 1801 may includeany quantity of interconnected buses and bridges based on specificapplication and an overall design constraint condition of the sendingapparatus or the response apparatus. The bus 1801 interconnects variouscircuits, and the circuits include a processor 1802, a storage medium1803, a bus interface 1804, and a user interface 1806.

The sending apparatus or the response apparatus connects a networkadapter 1805 and the like through the bus interface 1804 by using thebus 1801. The network adapter 1805 may be configured to implement asignal processing function of a physical layer in a wireless local areanetwork, and send and receive radio frequency signals by using anantenna 1807. In this application, the antenna 1807 is configured toimplement various information receiving and sending that are performedby the sending apparatus or the response apparatus in the foregoingmethod embodiments.

The user interface 1806 may connect to a user terminal, for example, akeyboard, a display, a mouse, or a joystick. The bus 1801 may furtherconnect to various other circuits, for example, a timing source, aperipheral device, a voltage regulator, and a power management circuit.These circuits are well-known in the art, and are not described indetail herein.

The processor 1802 is responsible for bus management and generalprocessing (including executing software stored in the storage medium1803). The processor 1802 may be implemented by using one or moregeneral purpose processors and/or dedicated processors. Examples of theprocessor include a microprocessor, a microcontroller, a DSP, and othercircuits that can execute software. Software should be broadlyinterpreted as instructions, data, or any combination thereof,regardless of whether the software is referred to as software, firmware,middleware, microcode, hardware description language, or the like, inthis application, the processor 1802 is configured to implement allprocessing performed by a first communications apparatus in theforegoing method embodiments except various information receiving andsending.

In addition, the storage medium 1803 is separated from the processor1802 in FIG. 18 . However, a person skilled in the art can easilyunderstand that the storage medium 1803 or any part thereof may belocated outside the sending apparatus or the response apparatus. Forexample, the storage medium 1803 may include a transmission line, acarrier waveform modulated by using data, and/or a computer productseparated from a wireless node. All these media are accessible to theprocessor 1802 through the bus interface 1804. Alternatively, thestorage medium 1803 or any part thereof may be integrated into theprocessor 1802, for example, may be a cache and/or a general register.In this application, the storage medium 1803 is configured to store acomputer program, and the computer program is executed by the processor1802 to implement all processing performed by the processor 1802.

In another possible product form, the sending apparatus or the responseapparatus may be configured as a general purpose processing system. Forexample, the general purpose processing system is usually referred to asa chip. The general purpose processing system includes one or moremicroprocessors that provide a processor function and an external memorythat provides at least a part of the storage medium 1803. All thesecomponents are connected to other supporting circuits by using anexternal bus architecture structure.

In another possible product form, the sending apparatus or the responseapparatus may also be implemented by using an application-specificintegrated circuit (application specific integrated circuit, ASIC)having a processor 1802, a bus interface 1804, and a user interface1806, and at least a part of the storage medium 1803 integrated in asingle chip.

In another possible product form, the sending apparatus or the responseapparatus may also be implemented by using one or morefield-programmable gate arrays (field-programmable gate array, FPGA), aprogrammable logic device (programmable logic device, PLD), acontroller, a state machine, a gate logic, a discrete hardwarecomponent, any other appropriate circuit, or any combination of circuitsthat can implement various functions described in this application.

All or some of the foregoing embodiments of this application may beimplemented by using software, hardware, firmware, or any combinationthereof. When software is used to implement the embodiments, theembodiments may be all or partially implemented in a form of a computerprogram product. The computer program product includes one or morecomputer instructions. When the computer program instructions are loadedand executed on a computer, the procedure or functions according to theembodiments of this application are all or partially generated. Thecomputer may be a general-purpose computer, a dedicated computer, acomputer network, or another programmable apparatus. The computerinstructions may be stored in a computer readable storage medium or maybe transmitted from a computer readable medium to another computerreadable medium. For example, the computer instructions may betransmitted from a website, computer, server, or data center to anotherwebsite, computer, server, or data center in a wired (for example, acoaxial cable, an optical fiber, or a digital subscriber line (DigitalSubscriber Line, DSL)) or wireless (for example, infrared, radio, ormicrowave) manner. The computer readable storage medium may be anyusable medium accessible by a computer, or a data storage device, suchas a server or a data center, integrating one or more usable media. Theusable medium may be a magnetic medium (for example, a floppy disk, ahard disk, or a magnetic tape), an optical medium (for example, a DVD),a semiconductor medium (for example, a solid state drive (Solid StateDisk, SSD)), or the like.

The following further provides another embodiment of this application.As shown in FIG. 20 , the method includes the following steps.

-   -   1. An initiator sends a series of TDD SSWs, where the frame may        be in two formats:    -   a. When an RA is unicast, the frame is sent to a specific        responder, in other words, BF training is performed in a        one-to-one correspondence. In this case, a frame structure of        the TDD SSW is the same as that of Intel. A purpose is to        control a length of the frame to be less than or equal to 27        bytes. Otherwise, an LDPC symbol is redundant. In this case, a        relatively long time is caused. If a frame sent to one responder        is also in a uniform format, the length may be greater than 27        bytes.    -   b. When an RA is broadcast or a special ID, the frame is used to        indicate a special time for sending a TDD SSW FBCK through        random contention and a corresponding time for returning TDD SSW        ACK, in other words, BF training is performed in a one-to-one or        one-to-many correspondence. However, an object of BF training is        unknown and is determined in a random contention manner. A frame        structure is shown in FIG. 21 .    -   2. The responder may perform RX beam scanning. If the responder        receives a TDD SSW, the responder uses an indicated responder        feedback offset as a start location, and then returns a TDD SSW        feedback in one slot randomly selected from one or more slots        (indicated by a number of slots for FBCK and ACK).    -   3. The Initiator uses an indicated initiator Ack offset as a        start location, and then returns a TDD SSW ACK to each responder        in a slot of each TDD SSW ACK in a sequence of receiving TDD SSW        FBCKs.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

1. A method, comprising: generating, by a sending apparatus, a firstframe; and sending, by the sending apparatus, the first frame to atleast two response apparatuses, wherein the first frame comprises atleast two pieces of sub-time resource indication information, andwherein each piece of sub-time resource indication information is in aone-to-one correspondence with one of the at least two responseapparatuses, and each piece of sub-time resource indication informationcomprises a time resource at which the corresponding response apparatussends feedback information for the first frame to the sending apparatusand a time resource at which the sending apparatus sends acknowledgmentinformation for the feedback information to the corresponding responseapparatus.
 2. The method according to claim 1, wherein the first framecomprises a time resource indication field and the time resourceindication field carries the at least two pieces of sub-time resourceindication information.
 3. The method according to claim 1, wherein thefirst frame further comprises a destination indication field and thedestination indication field is a broadcast address value.
 4. The methodaccording to claim 1, wherein each piece of sub-time resource indicationinformation further comprises an identifier subfield used to identifythe corresponding response apparatus.
 5. The method according to claim4, wherein the identifier subfield is an identifier with a length thatis obtained through calculation based on a medium access control (MAC)address of the corresponding response apparatus.
 6. The method accordingto claim 1, wherein each sub-time resource indication field furthercomprises an end indication subfield which indicates whether the timeresource indication field ends.
 7. The method according to claim 1,wherein the first frame further comprises a response apparatus quantityfield which indicates a quantity of at least two response apparatuses.8. The method according to claim 1, further comprising: sending, by thesending apparatus, a second frame to the at least two responseapparatuses, wherein the second frame comprises indication informationindicating a sending time of the first frame.
 9. A communicationapparatus, comprising: at least one processor and a computer-readablestorage medium, wherein the storage medium stores instructions that inresponse to being executed by the at least one processor, cause thecommunication apparatus to: generate a first frame; and send the firstframe to at least two response apparatuses, wherein the first framecomprises at least two pieces of sub-time resource indicationinformation, and wherein each piece of sub-time resource indicationinformation is in a one-to-one correspondence with one of the at leasttwo response apparatuses, and each piece of sub-time resource indicationinformation comprises a time resource at which the correspondingresponse apparatus sends feedback information for the first frame to thecommunication apparatus and a time resource at which the communicationapparatus sends acknowledgment information for the feedback informationto the corresponding response apparatus.
 10. The communication apparatusaccording to claim 9, wherein the first frame comprises a time resourceindication field and the time resource indication field carries the atleast two pieces of sub-time resource indication information.
 11. Thecommunication apparatus according to claim 9, wherein the first framefurther comprises a destination indication field and the destinationindication field is a broadcast address value.
 12. The communicationapparatus according to claim 9, wherein each piece of sub-time resourceindication information further comprises an identifier subfield used toidentify the corresponding response apparatus.
 13. The communicationapparatus according to claim 12, wherein the identifier subfield is anidentifier with a length that is obtained through calculation based on amedium access control (MAC) address of the corresponding responseapparatus.
 14. The communication apparatus according to claim 9, whereineach sub-time resource indication field further comprises an endindication subfield which indicates whether the time resource indicationfield ends.
 15. The communication apparatus according to claim 9,wherein the first frame further comprises a response apparatus quantityfield which indicates a quantity of at least two response apparatuses.16. A chip comprising: a processor configured to generate a first frameand control a transceiver pin to send the first frame to at least tworesponse apparatuses, wherein the first frame comprises at least twopieces of sub-time resource indication information, and wherein eachpiece of sub-time resource indication information is in a one-to-onecorrespondence with one of the at least two response apparatuses, andeach piece of sub-time resource indication information comprises a timeresource at which the corresponding response apparatus sends feedbackinformation for the first frame to a sending apparatus comprising thechip and a time resource at which the sending apparatus sendsacknowledgment information for the feedback information to thecorresponding response apparatus.
 17. The chip according to claim 16,wherein the first frame comprises a time resource indication field andthe time resource indication field carries the at least two piece ofsub-time resource indication information.
 18. The chip according toclaim 16, wherein the first frame further comprises a destinationindication field and the destination indication field is a broadcastaddress value.
 19. The chip according to claim 16, wherein each piece ofsub-time resource indication information further comprises an identifiersubfield used to identify the corresponding response apparatus.
 20. Thechip according to claim 19, wherein the identifier subfield is anidentifier with a length that is obtained through calculation based on amedium access control (MAC) address of the corresponding responseapparatus.